Classical Model Refuting Certain Loophole-Free Tests of Local Realism

We consider two recent experimental tests of local realism purporting to be loophole free and demonstrate that they can, in fact, be explained by a local, deterministic classical model. In particular, we show that apparent violations of the Clauser-Horne-Eberhard inequality can arise from the local dependence of coherence times on the settings of each polarizer due to the presence of additional vacuum modes. Consequently, different settings produce differing numbers of effective independent trials within a fixed coincidence window, suppressing singles counts and enhancing coincidence counts. The resulting contextual dependence permits a violation of the inequality.